The bq24079QW-Q1 is an integrated Li-ion linear charger and system power-path management
device targeted at space-constraint automotive applications such as telematics/eCall. The device
can operate from 4.35 V to 6.4 V and support charge currents up to 1.5 A. The input voltage range
with input overvoltage protection supports unregulated adapters. The USB input current limit
accuracy and start up sequence allow the bq24079QW-Q1 to meet the USB-IF inrush current
specification. Additionally, the input dynamic power management (VIN-DPM)
prevents the system load from crashing incorrectly configured USB sources.
The bq24079QW-Q1 features dynamic power-path management (DPPM) that powers the system
while simultaneously and independently charging the battery. The DPPM circuit reduces the charge
current when the input current limit causes the system output to fall to the DPPM threshold; thus,
supplying the system load at all times while monitoring the charge current separately. This feature
along with the 4.1-V battery regulation voltage helps to extend battery life time by reducing the
number of charge and discharge cycles on the battery, allowing for proper charge termination and
enabling the system to run with a defective or absent battery pack.
Additionally, the regulated system input enables instant system turn-on when plugged in
even with a totally discharged battery. The power-path management architecture also permits the
battery to supplement the system current requirements when the adapter cannot deliver the peak
system currents, enabling the use of a smaller adapter.
The battery is charged in three phases: conditioning, constant current, and constant
voltage. In all charge phases, an internal control loop monitors the IC junction temperature and
reduces the charge current if the internal temperature threshold is exceeded. The charger power
stage and charge current sense functions are fully integrated. The charger function has high
accuracy current and voltage regulation loops, charge status display, and charge termination. The
input current limit and charge current are programmable using external resistors.
The bq24079QW-Q1 is an integrated Li-ion linear charger and system power-path management
device targeted at space-constraint automotive applications such as telematics/eCall. The device
can operate from 4.35 V to 6.4 V and support charge currents up to 1.5 A. The input voltage range
with input overvoltage protection supports unregulated adapters. The USB input current limit
accuracy and start up sequence allow the bq24079QW-Q1 to meet the USB-IF inrush current
specification. Additionally, the input dynamic power management (VIN-DPM)
prevents the system load from crashing incorrectly configured USB sources.
The bq24079QW-Q1 features dynamic power-path management (DPPM) that powers the system
while simultaneously and independently charging the battery. The DPPM circuit reduces the charge
current when the input current limit causes the system output to fall to the DPPM threshold; thus,
supplying the system load at all times while monitoring the charge current separately. This feature
along with the 4.1-V battery regulation voltage helps to extend battery life time by reducing the
number of charge and discharge cycles on the battery, allowing for proper charge termination and
enabling the system to run with a defective or absent battery pack.
Additionally, the regulated system input enables instant system turn-on when plugged in
even with a totally discharged battery. The power-path management architecture also permits the
battery to supplement the system current requirements when the adapter cannot deliver the peak
system currents, enabling the use of a smaller adapter.
The battery is charged in three phases: conditioning, constant current, and constant
voltage. In all charge phases, an internal control loop monitors the IC junction temperature and
reduces the charge current if the internal temperature threshold is exceeded. The charger power
stage and charge current sense functions are fully integrated. The charger function has high
accuracy current and voltage regulation loops, charge status display, and charge termination. The
input current limit and charge current are programmable using external resistors.